difficultywise.md

Difficulty Distribution:

• LeetCode: 47 Easy, 45 Medium, 14 Hard
• GeeksforGeeks: 11 Easy, 19 Medium
• Coding Ninjas / Naukri Code360: 5 Easy, 7 Medium
• SPOJ: 2 Medium

Difficulty wise Categorized DSA Questions

Difficulty wise Categorized DSA Questions

LeetCode

Easy

• 3005. Count Elements With Maximum Frequency (Day_125)
• 111. Minimum Depth of Binary Tree (Day_116)
• 1. Two Sum (Day 011)
• 3550. Smallest Index With Digit Sum Equal to Index (Day 011)
• 1572. Matrix Diagonal Sum (Day 012)
• 724. Find Pivot Index (Day 013)
• 26. Remove Duplicates from Sorted Array (Day 038)
• 204. Count Primes (Day 035)
• 7. Reverse Integer (Day 035)
• 509. Fibonacci Number (Day 042)
• 70. Climbing Stairs (Day 082)
• 155. Min Stack (Day 082)
• 876. Middle of the Linked List (Day 074)
• 1290. Convert Binary Number in a Linked List to Integer (Day 085)
• 141. Linked List Cycle (Day 075)
• 83. Remove Duplicates from Sorted List (Day 077)
• 21. Merge Two Sorted Lists (Day 078)
• 2095. Delete the Middle Node of a Linked List (Day 083)
• 3606. Coupon Code Validator (Day 083)
• 2942. Find Words Containing Character (Day 034)
• 27. Remove Element (Day 045)
• 58. Length of Last Word (Day 048)
• 66. Plus One (Day 049)
• 67. Add Binary (Day 050)
• 3442. Maximum Difference Between Even and Odd Frequency (Day 051)
• 121. Best Time to Buy and Sell Stock (Day 052)
• 3423. Maximum Difference Between Adjacent Elements in a Circular Array (Day 053)
• 217. Contains Duplicate (Day 054)
• 14. Longest Common Prefix (Day 055)
• 136. Single Number (Day 059)
• 168. Excel Sheet Column Title (Day 061)
• 171. Excel Sheet Column Number (Day 065)
• 268. Missing Number (Day 066)
• 342. Power of Four (Day 064)
• 326. Power of Three (Day 063)
• 15. 3Sum (Day 062)
• 3330. Find the Original Typed String I (Day 072)
• 234. Palindrome Linked List (Day 073)
• 707. Design Linked List (Day 073)
• 1394. Find Lucky Integer in an Array (Day 076)
• 61. Rotate List (Day 081)
• 3622. Check Divisibility by Digit Sum and Product (Day_091)
• 1957. Delete Characters to Make Fancy String (Day_092)
• 203. Remove Linked List Elements (Day_094)
• 387. First Unique Character in a String (Day_095)
• 225. Implement Stack using Queues (Day_096)
• 232. Implement Queue using Stacks (Day_096)
• 513. Find Bottom Left Tree Value (Day_102)
• 112. Path Sum (Day_103)
• 3637. Trionic Array I (Day_105)
• 700. Search in a Binary Search Tree (Day_109)

Medium

• 99. Recover Binary Search Tree (Day_116)
• 287. Find the Duplicate Number (Day_117)
• 208. Implement Trie (Prefix Tree) (Day_126)
• 852. Peak Index in a Mountain Array (Day 013)
• 33. Search in Rotated Sorted Array (Day 014)
• 50. Pow(x, n) (Day 036)
• 54. Spiral Matrix (Day 034)
• 48. Rotate Image (Day 034)
• 240. Search a 2D Matrix II (Day 034)
• 75. Sort Colors (Day 078)
• 148. Sort List (Day 080)
• 430. Flatten a Multilevel Doubly Linked List (Day 080)
• 2894. Divisible and Non-divisible Sums Difference (Day 037)
• 25. Reverse Nodes in k-Group (Day 075)
• 142. Linked List Cycle II (Day 075)
• 82. Remove Duplicates from Sorted List II (Day 077)
• 2. Add Two Numbers (Day 079)
• 138. Copy List with Random Pointer (Day 079)
• 34. Find First and Last Position (Day 047)
• 35. Search Insert Position (Day 046)
• 6. Zigzag Conversion (Day 071)
• 19. Remove Nth Node From End of List (Day 073)
• 206. Reverse Linked List (Day 073)
• 3. Longest Substring Without Repeating Characters (Day 056)
• 567. Permutation in String (Day 030)
• 1910. Remove All Occurrences of a Substring (Day 030)
• 1047. Remove Adjacent Duplicates (Day 030)
• 151. Reverse Words in String (Day 029)
• 896. Monotonic Array (Day 028)
• 2022. Convert 1D Array Into 2D Array (Day 032)
• 867. Transpose Matrix (Day 032)
• 74. Search a 2D Matrix (Day 032)
• 443. String Compression (Day 031)
• 283. Move Zeroes (Day 024)
• 88. Merge Sorted Arrays (Day 024)
• 189. Rotate Array (Day 025)
• 1752. Check if Array is Sorted and Rotated (Day 025)
• 143. Reorder List (Day 090)
• 622. Design Circular Queue (Day_092)
• 641. Design Circular Deque (Day 093)
• 134. Gas Station (Day_096)
• 24. Swap Nodes in Pairs (Day_097)
• 222. Count Complete Tree Nodes (Day_098)
• 215. Kth Largest Element in an Array (Day_121)
• 3627. Maximum Median Sum of Subsequences of Size 3 (Day_098)
• 543. Diameter of Binary Tree (Day_099)
• 110. Balanced Binary Tree (Day_099)
• 100. Same Tree (Day_099)
• 101. Symmetric Tree (Day_100)
• 102. Binary Tree Level Order Traversal (Day_100)
• 103. Binary Tree Zigzag Level Order Traversal (Day_100)
• 104. Maximum Depth of Binary Tree (Day_100)
• 107. Binary Tree Level Order Traversal II (Day_100)
• 94. Binary Tree Inorder Traversal (Day_100)
• 199. Binary Tree Right Side View (Day_101)
• 987. Vertical Order Traversal of Binary Tree (Day_101)
• 437. Path Sum III (Day_103)
• 1161. Maximum Level Sum of a Binary Tree (Day_103)
• 236. Lowest Common Ancestor of a Binary Tree (Day_103)
• 1483. Kth Ancestor of a Tree Node (Day_104)
• 105. Construct Binary Tree from Preorder and Inorder Traversal (Day_105)
• 106. Construct Binary Tree from Inorder and Postorder Traversal (Day_105)
• 80. Remove Duplicates from Sorted Array II (Day_106)
• 701. Insert into a Binary Search Tree (Day_109)
• 1008. Construct Binary Search Tree from Preorder Traversal (Day_109)
• 109. Convert Sorted List to Binary Search Tree (Day_110)
• 450. Delete Node in a BST (Day_111)
• 98. Validate Binary Search Tree (Day_111)
• 81. Search in Rotated Sorted Array II (Day_106)
• 237. Delete Node in a Linked List (Day_107)
• 2385. Amount of Time for Binary Tree to Be Infected (Day_108)
• 114. Flatten Binary Tree to Linked List (Day_108)
• Kth Largest Element in BST (GeeksForGeeks, Medium) (Day 112)
• 230. Kth Smallest Element in a BST (LeetCode, Medium) (Day 112)
• 36. Valid Sudoku (LeetCode, Medium) (Day_130)
• 797. All Paths From Source to Target (LeetCode, Medium) (Day_137)
• 743. Network Delay Time (LeetCode, Medium) (Day_139)
• Minimum Spanning Tree (Prim's Algorithm) (GeeksForGeeks, Medium) (Day_140)
• Minimum Spanning Tree (Kruskal's Algorithm) (GeeksForGeeks, Medium) (Day_141)
• 1584. Min Cost to Connect All Points (LeetCode, Medium) (Day_142)

Hard

• 43. Multiply Strings (Day 044)
• 135. Candy Distribution (Day 043)
• 25. Reverse Nodes in k-Group (Day 075)
• 32. Longest Valid Parentheses (Day 085)
• 84. Largest Rectangle in Histogram (Day 086)
• 85. Maximal Rectangle (Day 088)
• 23. Merge k Sorted Lists (Day 089, Day 123)
• 632. Smallest Range Covering Elements from K Lists (LeetCode) - Hard (C++ Solution)
• 51. N-Queens (Day_129)
• 52. N-Queens II (Day_129)
• 37. Sudoku Solver (Day_130)
• 295. Find Median from Data Stream (Day_124)
• 2360. Longest Cycle in a Graph (Day_134)
• 1192. Critical Connections in a Network (Day_142)

GeeksforGeeks

Easy

• Selection Sort (Day 019)
• Bubble Sort (Day 019)
• Write a program to reverse an array or string (Day 023)
• Delete Middle Element of a Stack (Day 083)
• Reverse a Stack (Day 083)
• Sort a Stack (Day 084)
• Reverse a Queue (Day 094)
• Heap Implementation - Basic heap data structure implementation
• Heapify Algorithm - Basic heapify operation implementation
• Priority Queue Usage - Basic priority queue operations

Medium

• Book Allocation Problem (Day 016)
• Aggressive Cows (Day 017)
• Remove Loop in Linked List (Day 077)
• Sort linked list of 0s 1s 2s (Day 078)
• Heap Sort Implementation - Complete heap sort algorithm implementation
• Kth Smallest Element in Array - Find kth smallest element using heap
• Remove duplicates from an unsorted linked list (Day 078)
• N Queues in an Array (Day_097)
• First Negative Integer in Every Window of Size K (Day 095)
• Reverse First K Elements of Queue (Day 095)
• First Non-repeating Character in a Stream (Day_095)
• Interleave the First Half of the Queue with Second Half (Day_096)
• Sum of Max and Min of Window K in Array (Day_097)
• Count Leaves in Binary Tree (Day_098)
• Sum Tree (Day_099)
• 101. Symmetric Tree (Day_100)
• 104. Maximum Depth of Binary Tree (Day_100)
• 94. Binary Tree Inorder Traversal (Day_100)
• Boundary Traversal of Binary Tree (Day_101)
• Top View of Binary Tree (Day_102)
• Bottom View of Binary Tree (Day_102)
• Diagonal Traversal of Binary Tree (Day_102)
• Sum of Nodes on the Longest Path from Root to Leaf Node (Day_103)
• Maximum Sum of Non-adjacent Nodes (Day_104)
• Morris Traversal Implementation (Day_108)
• Inorder Predecessor and Successor (Day_111)
• Largest BST in a Binary Tree (Day_118)
• Merge two BSTs (Day_118)
• BFS of Graph (Day_132)
• DFS of Graph (Day_132)
• Detect Cycle in an Undirected Graph (Day_133)
• Detect Cycle in a Directed Graph (Day_134)
• Topological Sort (Day_135)
• Cycle Detection in Directed Graph using Kahn's Algorithm (Day_135)
• Shortest Path in Directed Acyclic Graph (Day_138)
• Shortest Path in an Unweighted Undirected Graph (Day_136)
• Flatten BST to Sorted List (Day_114)

Coding Ninjas / Naukri Code360

Easy

• Check Palindrome (Day 027)
• Insert An Element At Its Bottom In A Given Stack (Day 083)
• Replace Spaces with @40 (Day 030)
• Print Like A Wave (Day 033)
• subsequence of a string (Day 067)
• Print Adjacency List (Day_131)

Medium

• Redundant Brackets (Day 084)
• Minimum Cost To Make String Valid (Day 084)
• Sort linked list of 0s 1s 2s (Day 078)
• Next Smaller Element (Day 085)
• N Stacks In An Array (Day 088)
• Design a Stack That Supports getMin in O(1) Time and O(1) Extra Space (Day 090)

SPOJ

Medium

• EKO - Wood Cutting (Day 017)
• PRATA - Roti Prata (Day 018)